Optical virtual local area network

Abstract

The maximum number of virtual local area networks (VLANs) is increased beyond the number provided solely with the VLAN ID, by a factor related to the number of wavelengths of a Wavelength Division Multiplexing (WDM) used by a network switching. An optical VLAN number (OVLAN ID) is a combination of the VLAN ID from the packet header and a path or wavelength ID (WL ID) that identifies a selected one of available wavelengths of a WDM transmission line. An Optical VLAN (OVLAN) conversion table stores data of the OVLAN ID, the VLAN ID and optical path ID, for an optical VLAN node.

1. A switching method, for use in a VLAN (virtual local area network) including at least one WDM optical path, comprising:
 deriving a VLAN ID from a received packet; 
 deriving a wavelength ID value related to a carrier wavelength of the received packet; and 
 using at least both the VLAN ID value and the wavelength ID value for making an optical VLAN forwarding decision for the packet to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame. 
 
   
   
     2. The method of  claim 1 , including:
 managing a forwarding database storing packet records including received and forwarded values for VLAN ID, and carrier wavelength; and 
 said step of using further including searching the database for data forwarding information, and forwarding the packet in response to a result of said searching. 
 
   
   
     3. A computer readable media stored with computer readable data instructions that are executable for physically implementing the method of  claim 2 . 
   
   
     4. The method of  claim 1 , including:
 parsing a received packet and determining the presence of a valid VLAN ID field; and 
 performing said two steps of deriving and said step of using only when there is a valid VLAN ID field. 
 
   
   
     5. The method of  claim 4 , including:
 managing a forwarding database storing packet records including received and forwarded values for VLAN ID, and carrier wavelength; and 
 said step of using further including searching the database for data forwarding information, and forwarding the packet in response to a result of said searching. 
 
   
   
     6. The method of  claim 1 , including:
 parsing a received packet and determining the presence of a valid VLAN ID field; 
 determining if a set maximum VLAN ID capacity has been reached; and 
 performing said two steps of deriving and said step of using only when the maximum VLAN ID capacity has been reached. 
 
   
   
     7. The method of  claim 6 , including:
 managing a forwarding database storing packet records including received and forwarded values for VLAN ID, and carrier wavelength; and 
 said step of using further including searching the database for data forwarding information, and forwarding the packet in rcsponsc to a result of said searching. 
 
   
   
     8. A computer readable media stored with computer readable data instructions that are executable for physically implementing the method of  claim 1 . 
   
   
     9. A network node switching device for use in a VLAN (virtual local area network), comprising:
 means for switching a received packet at least from or to WDM optical paths, 
 means for deriving a VLAN ID from the received packet; 
 means for assigning a wavelength ID to the packet; and 
 means for making a forwarding decision for the packet based upon at least both a VLAN ID value and a wavelength ID value to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame. 
 
   
   
     10. The network node switching device of  claim 9 , wherein said means for assigning performs its function only when a forwarding database indicates a threshold value of used VLAN IDs has been reached. 
   
   
     11. The network node switching device of  claim 9 , wherein said means for assigning performs its function only when a valid VLAN ID is present in the received packet. 
   
   
     12. The network node switching device of  claim 9 , further including:
 means for managing a forwarding database storing packet records including received and forwarded values for VLAN ID and carrier wavelength. 
 
   
   
     13. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 1 . 
 
   
   
     14. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 2 . 
 
   
   
     15. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 4 . 
 
   
   
     16. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 5 . 
 
   
   
     17. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 6 . 
 
   
   
     18. A switch for forwarding a packet having a header with a VLAN ID, for use in controlling a link in a data transmission network to provide a VLAN identifying capacity greater than that provided solely by a VLAN ID carried by a frame, comprising:
 a port to receive the packet; 
 a port to forward the packet; 
 at least one of said ports having optical paths with WDM; 
 a parsing engine to derive a VLAN ID value based upon a VLAN field in the received packet; 
 a computer; and 
 a computer readable media stored with computer readable data instructions that are executable by said computer for physically implementing the method of  claim 7 . 
 
   
   
     19. A method of transmitting information, comprising:
 receiving first and second VLAN (Virtual Local Area Network) tagged frames with both frames having the same VLAN ID (Identification); 
 transmitting the first frame over an optical fiber with a first wavelength and of a WDM (Wavelength Division Multiplexing) network; and 
 transmitting the second frame over the optical fiber with a second wavelength different from the first wavelength and over the WDM (Wavelength Division Multiplexing) network.